Test #1:
skwire@hankoku /cygdrive/c/4
$ ls -al e*
-rwx------+ 1 skwire None 2037532760 Dec 18 07:51 email-1.zip
-rwx------+ 1 skwire None 2019501177 Dec 18 08:01 email-2.zip
-rwx------+ 1 skwire None 2010861617 Dec 18 08:07 email-3.zip
-rwx------+ 1 skwire None 2007484481 Dec 18 08:13 email-4.zip
-rwx------+ 1 skwire None 2003196991 Dec 18 08:19 email-5.zip
-rwx------+ 1 skwire None 2049079438 Dec 18 08:40 email-6.zip
-rwx------+ 1 skwire None 1058473649 Dec 18 08:48 email-7.zip
Notes:
1) 12GB+ directory with over half a million files in it.
2) Output mode #1, 2000 as the size setting.
3) It took about an hour for all seven zips to be created. This was using zero (0) for the compression setting (quickest mode).
Test #2:
skwire@hankoku /cygdrive/c/4
$ ls -al i*
-rwx------+ 1 skwire None 2956007035 Dec 18 09:12 images-1.zip
Notes:
1) Source folder has 3593 files in it comprising 2.75 GB of space.
2) Output mode #1, 3000 as the size setting.
3) Generated file is a 2.75GB zip.